PC power switch hook up

Asus motherboard / Asus motherboard
February 5, 2009 at 10:12:13
Specs: going to be XP, 2gb
Hey I've been trying to figure something out here.

My on/off power switch for the PC I am building. I never had this problem before until now. Okay my motherboard is an ASUS P4GV-LA (Guppy)

Checkout my pictures below as I have taken of this problem.

The first photo is the of switch I'm dealing with.


This second switch I am thinking of replacing the other one with but the ends don't match up.

This photo is of the motherboard as you can see the ends don't match up for both of the switches.


I was thinking of cutting the wires but I never did that before. Could use some ideas on these connectors.

See More: PC power switch hook up

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February 5, 2009 at 12:09:36
NONE of the links to your pictures work for me, and probably, they won't work for anyone else who tries them.
If you have to type a password or do some step in order to see the pictures yourself, that's not the kind of link to somthing anyone can access, unless we have instructions from you to go to some other address first and do something so we can access them.
E.g. links to pictures placed on the photobucket site are accessible to anyone, for a limited time.

Brand name system builders usually use a one piece female connector on the wiring from their case to the front panel header on the mboard (HP or Compaq sometimes call it the button board header or connector), and in any case they usually do NOT show you anywhere which pins are for what in that header - for the power switch, the hdd led, the power led, the reset switch if the case has one, etc.

Apparently this is an OEM only mboard - Asus itself has no info about it.

However, Asus (and other mboard makers that supply mboards to brand name system builders - e.g. HP, Compaq, Dell, Gateway, and most other brand name system builders DO NOT make the mboards themselves) does NOT normally change which pins are for what on that header, or on other headers on the mboard, even if it is an OEM only mboard.
If you want to know which pins are for what on any header on the mboard, if you download and look at the manual for any Asus mboard of a similar age, the pinout assignments are usually identical to those on OEM only mboards.
In this case, look at amboard manual for a socket 478 mboard, although it probably doesn't matter which socket it uses as long as it was made about the same time (or the pinouts may not have changed over time in any case).

As far as power switches on computer cases go, they are extremely reliable and it's extremely rare for them to become defective, but on some cases, the case button that presses on them can stick inwards and cause the power switch to be engaged all the time - in that case the mboard will shut down in a few seconds and not start up again until the button becomes unstuck again and you then press the button again - check for that.

All power switches for ATX cases with ATX mboards in them (or similar ATX types), and all Reset switches for AT and ATX cases are the same type of switch - momentary contact - they are on only when pressed in.
You can use any ATX power switch, or any Reset switch for an AT or ATX case, as a power switch.

The power switch for an AT system is normally attached directly to the power supply wiring and comes with the power supply, not the case. It switches the power supply on/off, not the mboard itself.
It is not the same type of switch as an ATX case mounted power switch or a reset switch - it's toggled either on or off. If you are trying to use one of those that you salvaged from some computer, it usually toggles so the switch shaft is in more when the switch is on, and out more when it's off.
You can't use one of those for the pins for the power switch on an ATX mboard - the mboard will behave similar to the way it does for a stuck case button with an ATX case power switch - the mboard will shut off after a few seconds when the switch is toggled on, the mboard not start up again, and it will do the same thing when you then toggle the switch off and then on, forever.

Almost always when someone thinks the power switch is no good, either they have it connected to the wrong pins on the ATX mboard, or something else is wrong - often that something is the power supply is failing or has failed completely.
If you briefly short the proper pins for the power switch on the ATX mboard and the mboard does not start up, there's probably nothing wrong with your orginal power switch, and the most likely thing is your power supply is failing or has failed completely.
Failing power supplies are common and can cause your symptoms.
Check your PS.
They often partially work, fans and hard drives spin, leds come on, yet you get no video and the mboard will not boot all the way.
See response 4 in this:

If the brand of the power supply is BESTEC, if it is still partially working, I recommend you DO NOT continue to fiddle with the computer until it fails completely - they are a lot more likely to fry something else when they fail compltely, most often the mboard!!
If it is a BESTEC and it has already failed completely, there is a high likleyhood the mboard will NOT boot even after you replace the power supply!

In most cases if you need to replace the power supply, it can be replaced with any decent standard sized ATX PS that has the same wattage capacity or greater.
Although, you may need more capacity than that.
If this mboard has a PCI-E X16 slot and you have a video card in it that has a fairly recent video chipset, or if you have an AGP slot and have installed a video card with a recent video chipset, you MAY need a power supply with more capacity. In that case, see the specs for the video card on the manufacturer's web site for the model - if the video chipset requires your system has a power supply with more than average capacity, that is stated somewhere in the specs - usually under system requirements - that may state you may need at least a xxx watt capacity, and it may also state the minimum amperage rating the PS must have at a certain voltage.

Standard PS/2 size - 86mm high, 150mm wide, 140mm deep, or 3 3/8" h x 5 7/8" w x 5 1/2" d , or very close to that, though the depth can be more or less for some PSs.

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February 5, 2009 at 12:14:47
I can't view the pics but it *may* be because my workplace has the site blocked. I'm getting the following message:

"You don't have permission to access /mypictures/p4gv-la_motherboard.JPG on this server"

Anyhow, here it is at the HP site:


What's the problem? There should be no need to cut any wires.

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February 5, 2009 at 12:32:52
I can't access the pictures either.

In addition to the above advice I would state that at most you may need to remove individual wires from a multi-wire connector or do as I do when I run into a situation where the connector does mate up.

I take wire cutters and cut the connector parallel to the wires. That will separate them into individual wires with a connector on the end. Best I can advise without knowing what you are dealing with.

One other thing to mention. If you are recycling an old case like an AT case you can't use the power switch in that type case. AT cases had ON/OFF power switches. ATX use momentary contact switches. Take care with that.

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Related Solutions

February 5, 2009 at 15:53:29
"I take wire cutters and cut the connector parallel to the wires. That will separate them into individual wires with a connector on the end"

I try to use a non-destructive method whenever possible. For instance, let's say I have a 3-pin plug that has only 2 wires & they're configured in locations 1-3, but I need them at 1-2. If you look closely, there *should* be some sort of plastic tab that secures the end of the wire in the plug. If you're careful, you can bent the tab slightly & it will release the wire...then all you have to do is insert it into location 2 & push it down until you hear it click/lock in place.

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February 5, 2009 at 16:41:50
Okay yeah I can understand that problem you. I had it to here on firefox. Try viewing my pictures at http://gtpals.com/mypictures/ :)

Thanks guys for the input. Though jam are you talking about bending the little end deals on the motherboard? I don't have black ends that fit in it so.

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